/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */
package com.github.benmanes.caffeine.openjdk.concurrent.concurrenthashmap;

import static java.util.concurrent.TimeUnit.MILLISECONDS;

import java.time.Duration;
import java.util.List;
import java.util.Map;
import java.util.SplittableRandom;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.function.Supplier;

import org.testng.annotations.Test;

import com.github.benmanes.caffeine.cache.Caffeine;

/*
 * @test
 * @bug 4486658
 * @summary Exercise multithreaded maps, by default ConcurrentHashMap.
 * Multithreaded hash table test.  Each thread does a random walk
 * though elements of "key" array. On each iteration, it checks if
 * table includes key.  If absent, with probability pinsert it
 * inserts it, and if present, with probability premove it removes
 * it.  (pinsert and premove are expressed as percentages to simplify
 * parsing from command line.)
 * @library /test/lib
 * @run main/timeout=1600 MapLoops
 */

/*
 * @test
 * @summary Exercise multithreaded maps, using only heavy monitors.
 * @requires os.arch=="x86" | os.arch=="i386" | os.arch=="amd64" | os.arch=="x86_64" | os.arch=="aarch64" | os.arch == "ppc64" | os.arch == "ppc64le" | os.arch == "riscv64" | os.arch == "s390x"
 * @requires vm.debug
 * @library /test/lib
 * @run main/othervm/timeout=1600 -XX:LockingMode=0 -XX:+VerifyHeavyMonitors MapLoops
 */
@SuppressWarnings({"InconsistentOverloads", "InterruptedExceptionSwallowed",
  "NonFinalStaticField", "rawtypes", "SystemOut", "unchecked", "Var", "Varifier"})
public class MapLoops {
    static final long LONG_DELAY_MS = 10_000;
    static int nkeys       = 1000; // 10_000
    static int pinsert     = 60;
    static int premove     = 2;
    static int maxThreads  = 100;
    static int nops        = 10000; // 100_000
    static int removesPerMaxRandom;
    static int insertsPerMaxRandom;

    @Test
    public void bounded() throws Exception {
      var pool = Executors.newCachedThreadPool();
      try {
        test(pool, () -> Caffeine.newBuilder()
            .expireAfterWrite(Duration.ofNanos(Long.MAX_VALUE))
            .maximumSize(Long.MAX_VALUE)
            .build().asMap());
      } finally {
        pool.shutdown();
      }
    }

    @Test
    public void unbounded() throws Exception {
      var pool = Executors.newCachedThreadPool();
      try {
        test(pool, () -> Caffeine.newBuilder().build().asMap());
      } finally {
        pool.shutdown();
      }
    }

    public void test(ExecutorService pool, Supplier<Map> supplier) throws Exception {

//        Class mapClass = null;
//        if (args.length > 0) {
//            try {
//                mapClass = Class.forName(args[0]);
//            } catch (ClassNotFoundException e) {
//                throw new RuntimeException("Class " + args[0] + " not found.");
//            }
//        } else {
//          mapClass = java.util.concurrent.ConcurrentHashMap.class;
//        }
//
//        if (args.length > 1) {
//          maxThreads = Integer.parseInt(args[1]);
//        }
//
//        if (args.length > 2) {
//          nkeys = Integer.parseInt(args[2]);
//        }
//
//        if (args.length > 3) {
//          pinsert = Integer.parseInt(args[3]);
//        }
//
//        if (args.length > 4) {
//          premove = Integer.parseInt(args[4]);
//        }
//
//        if (args.length > 5) {
//          nops = Integer.parseInt(args[5]);
//        }

        // normalize probabilities wrt random number generator
        removesPerMaxRandom = (int)(premove/100.0 * 0x7FFFFFFFL);
        insertsPerMaxRandom = (int)(pinsert/100.0 * 0x7FFFFFFFL);

//        System.out.print("Class: " + mapClass.getName());
        System.out.print(" threads: " + maxThreads);
        System.out.print(" size: " + nkeys);
        System.out.print(" ins: " + pinsert);
        System.out.print(" rem: " + premove);
        System.out.print(" ops: " + nops);
        System.out.println();

        int k = 1;
        int warmups = 2;
        var throwables = new CopyOnWriteArrayList<Throwable>();
        for (int i = 1; i <= maxThreads;) {
            test(pool, i, nkeys, supplier, throwables);
            if (warmups > 0) {
              --warmups;
            } else if (i == k) {
                k = i << 1;
                i = i + (i >>> 1);
            }
            else if (i == 1 && k == 2) {
                i = k;
                warmups = 1;
            } else {
              i = k;
            }
        }
        pool.shutdown();
        if (! pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS)) {
          throw new Error();
        }

        if (! throwables.isEmpty()) {
          throw new Error
              (throwables.size() + " thread(s) terminated abruptly.");
        }
    }

    static Integer[] makeKeys(int n) {
        SplittableRandom rnd = new SplittableRandom();
        Integer[] key = new Integer[n];
        for (int i = 0; i < key.length; ++i) {
          key[i] = rnd.nextInt();
        }
        return key;
    }

    static void shuffleKeys(Integer[] key) {
        SplittableRandom rnd = new SplittableRandom();
        for (int i = key.length; i > 1; --i) {
            int j = rnd.nextInt(i);
            Integer tmp = key[j];
            key[j] = key[i-1];
            key[i-1] = tmp;
        }
    }

    void test(Executor pool, int i, int nkeys,
        Supplier<Map> supplier, List<Throwable> throwables) throws Exception {
        System.out.print("Threads: " + i + "\t:");
        Map<Integer, Integer> map = supplier.get();
        Integer[] key = makeKeys(nkeys);
        // Uncomment to start with a non-empty table
        //        for (int j = 0; j < nkeys; j += 4) // start 1/4 occupied
        //            map.put(key[j], key[j]);
        LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
        CyclicBarrier barrier = new CyclicBarrier(i+1, timer);
        SplittableRandom rnd = new SplittableRandom();
        for (int t = 0; t < i; ++t) {
          pool.execute(new Runner(map, key, barrier, rnd.split(), throwables));
        }
        barrier.await();
        barrier.await();
        long time = timer.getTime();
        long tpo = time / (i * (long)nops);
        System.out.print(LoopHelpers.rightJustify(tpo) + " ns per op");
        double secs = time / 1000000000.0;
        System.out.println("\t " + secs + "s run time");
        map.clear();
    }

    static class Runner implements Runnable {
        final Map<Integer,Integer> map;
        final Integer[] key;
        final CyclicBarrier barrier;
        final SplittableRandom rnd;
        final List<Throwable> throwables;
        int position;
        int total;

        Runner(Map<Integer,Integer> map,
               Integer[] key,
               CyclicBarrier barrier,
               SplittableRandom rnd,
               List<Throwable> throwables) {
            this.map = map;
            this.key = key;
            this.barrier = barrier;
            this.rnd = rnd;
            this.throwables = throwables;
            position = key.length / 2;
        }

        int step() {
            // random-walk around key positions, bunching accesses
            int r = rnd.nextInt(Integer.MAX_VALUE);
            position += (r & 7) - 3;
            while (position >= key.length) {
              position -= key.length;
            }
            while (position < 0) {
              position += key.length;
            }

            Integer k = key[position];
            Integer x = map.get(k);

            if (x != null) {
                if (x.intValue() != k.intValue()) {
                  throw new Error("bad mapping: " + x + " to " + k);
                }

                if (r < removesPerMaxRandom) {
                    if (map.remove(k) != null) {
                        position = total % key.length; // move from position
                        return 2;
                    }
                }
            }
            else if (r < insertsPerMaxRandom) {
                ++position;
                map.put(k, k);
                return 2;
            }

            // Uncomment to add a little computation between accesses
            //            total += LoopHelpers.compute1(k.intValue());
            total += r;
            return 1;
        }

        @Override
        public void run() {
            try {
                barrier.await();
                int ops = nops;
                while (ops > 0) {
                  ops -= step();
                }
                barrier.await();
            }
            catch (Throwable throwable) {
                synchronized (System.err) {
                    System.err.println("--------------------------------");
                    throwable.printStackTrace();
                }
                throwables.add(throwable);
            }
        }
    }
}
